The height of a mass oscillating vertically on an ideal spring is given by y(t) = Asin (ωt-Ψ) where t is time. The period, T, of this motion is _________.
a. T= A/2 πω
b. T= π/Ψ²
c. T= ω²/A
d. T= 2 π/ω
e. T= πΨ